Shaving heads constructed in this manner and known, for example, from U.S. Pat. No. 4,271,590 have the advantage that for cleaning purposes and for the replacement of damaged or worn down shaving foils they can be easily disassembled and refitted, also by laymen and inexperienced users, without exposing the delicate shaving foil to the risk of damage. The manufacture of the exchangeable frame and the mounting of the shaving foil thereon can be accomplished in an injection-molding process, thus eliminating the need for additional operation cycles.
To enable the shaving foil to yield under shaving pressure in cooperation with the lower cutter also when it is mounted in an exchangeable frame, so that relative contact between foil and cutter is maintained and damage to the shaving foil due to buckling and flexing is avoided, a variety of attempts have been made which, however, have been unsatisfactory so far and, as a result, were not adopted in series production, in contrast to the yielding mounting of the shaving foil in the shaving head frame directly.
Accordingly, the arrangement of torsion springs as an integral part of the exchangeable frame appears at first advantageous because it, too, dispenses with the need for an additional operation, however, it has been established that this type of spring suspension can only be implemented with relatively stiff springs because of the necessary thickness of the material, and that the damping of vibrations incited by the working motion of the lower cutter is insufficient (U.S. Pat. No. 4,271,590, Japanese Utility Pat. Application No. 49-2702). In addition, the exchangeable frame disclosed in the last-mentioned reference cannot be removed from the shaving head frame by simple means.
On the basis of this state of the art, it is an object of the present invention to ensure in a shaving head of the type initially referred to that the shaving foil is in a position to readily follow the yielding motion of the lower cutter under shaving pressure, while remaining locked against entrainment by the working motion of the lower cutter, and to ensure ready removal of the shaving foil together with the exchangeable frame at any time.